1. Field of the Invention
The present invention pertains to pipe clamp assemblies, and in particular to pipe clamp assemblies having a live loading feature for maintaining desired clamping pressures.
2. Description of the Related Art
Pipe clamp assemblies are well known for joining one pipe to another pipe, to a fixture or a hose, for example. These types of clamps usually rely on threaded fasteners to maintain clamping pressure. Examples are found in U.S. Pat. Nos. 4,488,743; 4,871,181; 5,456,447; 1,317,963; 3,938,832; and 5,024,453.
However, in some applications the pipe joint is routinely taken apart or "broken-down" for cleaning or periodic maintenance. In the food industry, for example, where clean in place practices are not followed, piping systems are taken apart for periodic cleaning of their interior surfaces to maintain sanitary conditions. If pipes of this type are connected with the above-described conventional fasteners having bolts and nut components employed to apply pressure to pipe flanges, time and labor needed for periodic cleaning is increased.
Accordingly, a number of so-called "quick-acting" pipe clamp assemblies have been proposed to address this need. Examples are given in U.S. Pat. Nos. 1,093,868; 3,181,901; 3,966,240; and 2,449,795. These quick-acting clamp assemblies typically include a clamping collar formed in two parts which are hinged together, and which have fastening flanges opposite the hinge. A threaded fastener, which is typically permanently mounted to one flange with a pivot connection swings adjacent the other flange, and a threaded knot is advanced along the bolt to engage the opposite flange, drawing the flanges together and hence tightening the joint. The same concept has been applied to a band clamp or so-called "hose clamp", as described in U.S. Pat. No. 5,329,673. This arrangement also includes spring bias means for maintaining clamping pressure. An example of another hose clamp with spring bias means is given in U.S. Pat. No. 4,819,307. Use of spring bias means for maintaining clamping assembly is indicated where a piping system subject to significant vibrations or materials in the pipe joint may undergo a change such that the clamping pressure might lessen. Accordingly, spring pressure is relied upon to adjust the clamp, such that desired clamping pressure on the joint is maintained despite such changes. U.S. Pat. No. 4,429,847 shows a rigid pipe clamp with threaded fasteners, and employing spring washers. However, the clamp assembly is not of the quick-acting type and a need still exists for a quick-acting clamp assembly with improved live loading characteristics.
It is an object of the present invention to provide a clamping assembly of the quick-acting type.
Another object of the present invention is to provide a clamping assembly of the above-described type where clamping pressure is provided by a threaded fastener with a nut movable along a pivotally mounted bolt.
A further object of this invention is to provide a clamping assembly of the above-described type where a resilient bias means is employed to augment the clamping pressure when necessary.
Another object of the present invention is to provide a clamping assembly in which the spring bias means is located within a nut assembly so as to be automatically deployed when a pipe joint is first assembled.
This and other objects of the present invention are provided in a live loading clamp nut assembly, comprising:
a body having first and second opposed ends and defining an internally threaded bore for receiving a threaded bolt extending along a predefined axis; PA1 a cage having first and second opposed ends, for receiving the body and dimensioned so that the body is free to move along the axis; and PA1 spring bias means within the cage between the cage first end and the body first end for urging the body toward the second end of the cage. PA1 a nut member having first and second opposed ends and extending along a predefined axis, the nut member including a body with a stepped end wall, a central part having a free end adjacent the nut member first end, and extending from the end wall with the free end projecting beyond the end wall, and the nut member further defining a central passageway extending along the axis from the second end of the nut member to the free end of the central part; PA1 a spring cage having first and second opposed ends, an outer shell extending along the axis, between the first and the second ends, an inner sleeve within the outer shell, extending from the spring cage first end toward the spring cage second end and cooperating with the outer shell to form an internal cavity; PA1 resilient bias means in the internal cavity of the spring cage; and PA1 the forward end wall of the nut member received in the internal cavity of the spring cage. PA1 first and second pairs, each having first and second ends, hinged together at the first ends and having outwardly projecting shoulders at the second ends; PA1 a bolt pinned at one end to the first shoulder so as to be swingable adjacent the second shoulder; PA1 a nut assembly for threadingly engaging the bolt so as to engage the second shoulder to draw the first and the second pairs together, the nut assembly comprising:
Further objects of the present invention are provided in a live loading clamp nut assembly, comprising:
Further objects of the present invention are provided in a live loading clamping assembly, comprising:
a nut member having first and second opposed ends and extending along a predefined axis, the nut member including a body with a stepped end wall, a central part having a free end adjacent the nut member first end, and extending from the end wall with the free end projecting beyond the end wall, and the nut member further defining a central passageway extending along the axis from the second end of the nut member to the free end of the central part; PA2 a spring cage having first and second opposed ends, an outer shell extending along the axis, between the first and the second ends, an inner sleeve within the outer shell, extending from the spring cage first end toward the spring cage second end and cooperating with the outer shell to form an internal cavity; PA2 resilient bias means in the internal cavity of the spring cage; and PA2 the forward end wall of the nut member received in the internal cavity of the spring cage.